# US 2025/0147408 A1 · Phase shift mask and method for manufacturing phase shift mask > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0147408 A1 - Document ID: US20250147408A1 - Status: Published application - Kind: A1 - Application number: 18/833,854 - Filed: 2023-01-30 - Published: 2025-05-08 - Earliest claimed: 2022-01-31 - Assignees: Tekscend Photomask Corp. - Applicants: Tekscend Photomask Corp. - Inventors: Naoto YONEMARU; Kyoko KUROKI; Yosuke KOJIMA - Web page: https://patentgrep.com/patent/US20250147408A1 ## CPC - G03F 1/32: Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof - G03F 1/26: Phase shift masks [PSM]; PSM blanks; Preparation thereof - G03F 1/48: Protective coatings - G03F 1/72: Repair or correction of mask defects - G03F 1/80: Etching - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) ## Abstract There are provided a phase shift mask having a small number of haze defects, that is, a phase shift mask capable of sufficiently suppressing occurrence of haze, and a method for manufacturing the phase shift mask. A phase shift mask (100) according to the present embodiment is a phase shift mask having a circuit pattern by application of exposure light having a wavelength of 200 nm or less, the phase shift mask including a substrate (11), a phase shift film (12) that is formed on the substrate (11) and has a circuit pattern, and a protective film (13) that is formed on an upper surface (12t) and a side surface (12s) of the phase shift film (12), in which the phase shift film (12) enables adjustment of each of phase and transmittance with respect to the exposure light to be transmitted to a predetermined extent, the protective film (13) has a refractive index n in a range of 1.2 or more and 2.6 or less with respect to the exposure light and an attenuation coefficient k in a range of 0.0 or more and 0.4 or less, and in a case where a film thickness of the phase shift film (12) is denoted by d1 and a film thickness of the protective film (13) is denoted by d2, d2 is thinner than d1, and d2 is 15 nm or less. ## Claims ### Claim 1 A phase shift mask having a circuit pattern by application of exposure light having a wavelength of 200 nm or less, the phase shift mask comprising: a transparent substrate; a phase shift film that is formed on the transparent substrate and has a circuit pattern; and a gas permeation protective film that is formed on an upper surface and a side surface of the phase shift film, wherein the phase shift film enables adjustment of each of phase and transmittance with respect to the exposure light to be transmitted to a predetermined extent, the gas permeation protective film has a refractive index in a range of 1.2 or more and 2.6 or less with respect to the exposure light and an attenuation coefficient in a range of 0.0 or more and 0.4 or less, and in a case where a film thickness of the phase shift film is denoted by d1 and a film thickness of the gas permeation protective film is denoted by d2, d2 is thinner than d1, and d2 is 15 nm or less. ### Claim 2 (depends on 1) The phase shift mask according to claim 1, wherein the gas permeation protective film contains at least one selected from a hafnium metal and a hafnium compound, and the hafnium compound contains hafnium and contains at least one selected from nitrogen, oxygen, carbon, or fluorine. ### Claim 3 (depends on 1) The phase shift mask according to claim 1, wherein the gas permeation protective film contains silicon and contains at least one selected from nitrogen, oxygen, or carbon. ### Claim 4 (depends on 1) The phase shift mask according to claim 1, wherein the gas permeation protective film contains aluminum and contains at least one selected from nitrogen, oxygen, or carbon. ### Claim 5 (depends on 1) The phase shift mask according to claim 1, wherein the phase shift film has resistance to oxygen-containing chlorine-based etching and is etchable by fluorine-based etching. ### Claim 6 (depends on 1) The phase shift mask according to claim 1, wherein the phase shift film contains silicon and contains at least one selected from a transition metal, nitrogen, oxygen, or carbon, and the transition metal is at least one selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, tantalum, or tungsten. ### Claim 7 (depends on 1) The phase shift mask according to claim 1, wherein a ratio of a surface reflectivity of the gas permeation protective film to a surface reflectivity of the phase shift film is in a range of 0.4 or more and 1.2 or less. ### Claim 8 (depends on 1) The phase shift mask according to claim 1, wherein the gas permeation protective film is also formed on the transparent substrate. ### Claim 9 (depends on 1) A method for manufacturing the phase shift mask according to claim 1, the method comprising: forming a phase shift film on the transparent substrate; forming a light shielding film on the phase shift film; forming a resist pattern on the light shielding film formed on the phase shift film; forming a pattern on the light shielding film by oxygen-containing chlorine-based etching after forming the resist pattern; forming a pattern on the phase shift film by fluorine-based etching after forming the pattern on the light shielding film; removing the resist pattern after forming the pattern on the phase shift film; removing the light shielding film from the phase shift film on which the pattern is formed by oxygen-containing chlorine-based etching after removing the resist pattern; performing a defect inspection after removing the resist pattern and before removing the light shielding film or after removing the light shielding film; correcting the light shielding film or the phase shift film at a defective portion in a case where a defect is detected in the defect inspection; and forming the gas permeation protective film on an upper surface and a side surface of the phase shift film on which the pattern is formed after the correction. ### Claim 10 (depends on 9) The method for manufacturing the phase shift mask according to claim 9, wherein, in the forming of the gas permeation protective film, the gas permeation protective film is also formed on the transparent substrate. ### Claim 11 (depends on 2) The phase shift mask according to claim 2, wherein the phase shift film has resistance to oxygen-containing chlorine-based etching and is etchable by fluorine-based etching. ### Claim 12 (depends on 3) The phase shift mask according to claim 3, wherein the phase shift film has resistance to oxygen-containing chlorine-based etching and is etchable by fluorine-based etching. ### Claim 13 (depends on 4) The phase shift mask according to claim 4, wherein the phase shift film has resistance to oxygen-containing chlorine-based etching and is etchable by fluorine-based etching. ### Claim 14 (depends on 2) The phase shift mask according to claim 2, wherein the phase shift film contains silicon and contains at least one selected from a transition metal, nitrogen, oxygen, or carbon, and the transition metal is at least one selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, tantalum, or tungsten. ### Claim 15 (depends on 3) The phase shift mask according to claim 3, wherein the phase shift film contains silicon and contains at least one selected from a transition metal, nitrogen, oxygen, or carbon, and the transition metal is at least one selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, tantalum, or tungsten. ### Claim 16 (depends on 4) The phase shift mask according to claim 4, wherein the phase shift film contains silicon and contains at least one selected from a transition metal, nitrogen, oxygen, or carbon, and the transition metal is at least one selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, tantalum, or tungsten. ### Claim 17 (depends on 5) The phase shift mask according to claim 5, wherein the phase shift film contains silicon and contains at least one selected from a transition metal, nitrogen, oxygen, or carbon, and the transition metal is at least one selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, tantalum, or tungsten. ### Claim 18 (depends on 2) The phase shift mask according to claim 2, wherein a ratio of a surface reflectivity of the gas permeation protective film to a surface reflectivity of the phase shift film is in a range of 0.4 or more and 1.2 or less. ### Claim 19 (depends on 3) The phase shift mask according to claim 3, wherein a ratio of a surface reflectivity of the gas permeation protective film to a surface reflectivity of the phase shift film is in a range of 0.4 or more and 1.2 or less. ### Claim 20 (depends on 4) The phase shift mask according to claim 4, wherein a ratio of a surface reflectivity of the gas permeation protective film to a surface reflectivity of the phase shift film is in a range of 0.4 or more and 1.2 or less.